Verificationism

1. Verificationism

2. Classical Empiricism Last time we learned about the idea theory. Although it wasn’t confined to the empiricists, most of them ascribed to it (Locke, Berkeley, and Hume being the most notable). Empiricism was variously the doctrine that all ideas “came from” experience, or that all knowledge did, or both. (Usually both.)

3. Classical Empricism Empiricism had its problems, in addition to those that the idea theory suffered from: Experience tells you what is, not what must be/ should be/ will be. Yet we can know some of these things. Poverty of the stimulus: We figure out things like language use faster than experience is capable of teaching us. This suggests innateness.

4. Positivism The French philosopher/ first Western sociologist Isidore Auguste Marie François Xavier Comte (1798-1857) theorized that society progressed in three stages: from the theological, to the metaphysical, to the “positive.”

5. Positivism In the theological stage, people believe any silly or magical thing their ancestors attributed to the gods. Next, in the metaphysical stage gods go out of the picture, but are replaced with unjustified “metaphysical” assumptions (e.g. universal human rights). Finally, in the positive stage, the truth of our beliefs is “positively” determined. Compte thought science was the only source of positive determination.

6. Logical Empiricism/ Positivism Around the 1920’s in Vienna and Berlin certain philosophical doctrines became popular, and their adherents were variously known as Logical Empiricists or Logical Positivists (sometimes neo-Positivists). Notable names included Rudolf Carnap, Hans Reichenbach, and A.J. Ayer.

7. Empiricist Criterion of Cognitive Significance According to the logical positivists, in order for a sentence to have cognitive significance (to be meaningful), it had to have verification conditions. (‘Verification’ is a Latinate English word < ‘veri-’ true + ‘facere’ to make. Verification conditions are conditions under which the truth of a statement can be conclusively established.)

8. Empiricist Criterion of Cognitive Significance In fact, the positivists maintained that the meaning of a sentence was its verification conditions. So a sentence with no verification conditions– where no experience can establish its truth– is meaningless.

9. Truth vs. Verification Many philosophers (even today) have identified the meaning of a sentence with its truth conditions. These are the circumstances in which the sentence would be true. But the positivists went farther– they held that the meaning of a sentence was its verification conditions– the circumstances in which we would know the sentence was true.

10. The Elimination of Metaphysics This was part of a radical philosophical agenda, which included “the elimination of metaphysics.” The idea was to view many philosophical problems of the past (and also many religious claims) as meaningless disputes that could simply be ignored.

11. The Elimination of Metaphysics Example: In a religion where God is beyond human experience, the positivists would say that “God exists” is neither true nor false but meaningless, since no experience could verify it. Kant, Hegel, and Heidegger were also big targets for the positivists. Example Hegel quote: “But the other side of its Becoming, History, is a conscious, self-meditating process — Spirit emptied out into Time.”

12. The Elimination of Metaphysics The positivists even wanted to eliminate a lot of more down-to-Earth metaphysics: Modality: We can only experience what is, not what could possibly be. So statements about what is (merely) possible are meaningless. Normativity: We can only experience what is, not what should morally be. So statements about what is good or bad are meaningless.

13. The New Science There was also a scientific impetus to logical positivism (beyond the just pro-science message of positivism). Kant influentially held that Euclidean geometry was synthetic a priori, and that our experience must be as of a Euclidean spacetime. But the Minkowskispacetime in relativity is non-Euclidean.

14. Einstein How do you respond to opponents (classical physics) that think their theory is knowable in advance of any argument or evidence? Einstein responded by operationalizing: imagining rigid rods extending in all directions, and clocks at various points. That is, his arguments were couched in terms of what you could measure or experience (rather than straightforwardly in terms of what was true).

15. Quantum Mechanics Quantum mechanics also had metaphysical problems of its own. Several counterintuitive experiments seemed to suggest that the basic laws of the universe were not quite consistent with the laws of logic (e.g. the distribution laws). This led some physicists to simply deny that there were questions to be answered beyond “what do we observe/ experience?”– no questions like “what is the reality causing the appearances?”

16. Empiricist Semantics According to the positivists, the elimination of metaphysics followed from the correct account of meaning. When we understood that meaning = verification conditions, then we would see that ‘the Absolute is perfect’ or ‘God exists’ can’t possibly have meanings. Then we would be free to look into more promising, resolvable philosophical questions.

17. Protocol Sentences We single out a certain, small set of sentences to be the “protocol” or “observation” sentences. These sentences are all very simple syntactically, along the lines of: ‘that is red.’ The importance of the protocol sentences is that they can be immediately verified. To tell whether ‘that is red’ is verified (is true), you just have to look.

18. Non-Protocol Sentences All the other meaningful sentences (according to the verificationist) are defined in terms of the protocol sentences and the logical vocabulary (AND, OR, NOT, ALL, SOME, NO, etc.). For example ‘That is an arthropod’ := That is an animal AND it has a jointed body AND it has segmented legs.

19. Non-Protocol Sentences Obviously these sorts of definitions work best with scientific terminology like ‘arthropod,’ but the positivists were happy with that. It could turn out that much of our ordinary talk was not strictly speaking meaningful, but needed to be regimented in a more scientific language.

20. Protocol Sentences There was some measure of debate among the positivists regarding which sentences actually qualified as protocol sentences. The simpler the qualities they are about (e.g. ‘that is red’ ‘that is warm’ ‘this is joy’) the easier it is to argue that they can be verified immediately, but the harder it is to define the rest of the sentences (try defining “Obama is the president of the US” in terms of what things are red, warm, joy, etc.!

21. Protocol Sentences On the other hand, it’s easier to define more abstract things if we let sentences like ‘That is a chair’ or ‘That is a person’ be protocol sentences. However, can these things really be immediately verified? Our observations don’t seem to guarantee that something is a chair (it might be a fake chair, or the reflection of a chair, or…)

22. Carnap’sAufbau In the Aufbau (The Logical Structure of the World), Carnap undertook an ambitious project to outline how one could translate all “high-level” talk (e.g. “the train to Vienna is running late”) into talk about sensations at coordinate points in the visual field (“quality q is at point-instant x;y;z;t” [actually it was even more ambitious]). I should note that Carnap himself wasn’t much of a fan of the Aufbau after completing it.

23. Verificationist Semantics So here’s the picture: The meaning of a sentence is the set of experiences that would verify it. Protocol (observation) sentences are directly connected with their verification conditions: we can immediately tell whether they are verified in any particular circumstance. Non-protocol sentences inherit their verification conditions from the protocol sentences they are logically constructed out of.

24. Special Exception One exception was made: logic and mathematics were held to be meaningful, even though its hard to state (for example) what experiences would confirm “2 + 2 = 4.” Intuitionism (constructivism) was a positivist-influenced, non-classical approach to logic and mathematics that said that only provable formulas (only “mathematically verifiable” formulas) were true (denial of excluded middle).

25. Comparison with the idea theory

26. The Idea Theory Here were the essential parts of the idea theory: • Words and sentences are the visible, conventional signs of ideas. • Ideas represent things in the world by resembling (non-conventional) them. • We can treat the meaning of a word as either the idea it is a sign of, or the thing that idea represents (it doesn’t really matter).

27. Verificationism Verificationism is similar. A word or a sentence was conventionally associated with a set of experiences. Those experiences verify (“make true,” a non-conventional relation) that things in the world are a certain way because of a perfect correlation between the experiences and the states they verify. Sometimes this correlation was enforced by an idealist worldview, or a view on which the external world was logically constructed from sense data.

28. Representation is Not an Equivalence Relation A main problem for the idea theory was its identification of representation with resemblance. While resemblance is an equivalence relation (reflexive, symmetric, and transitive), representation is not.

29. Reflexivity But the verificationist thinks that the meaning of a sentence is the experience(s) that would verify it. Thus it follows (correctly) that most sentences do not represent themselves, because most sentences don’t verify themselves (exception: the sentence “This is a sentence”).

30. Abstract Concepts Idea theorists, as we saw, also had a problem with abstract ideas, as no picture equally resembles a fat man and a skinny man. One potential line of response we saw was to let abstract ideas be a collection of ideas, and to say that the collection represented what is common (shared by) all the items in the collection.

31. Abstract Concepts The verificationist strategy was similar: the meaning of ‘x is a dog’ was the collection of experiences that would verify it. However, these experiences need not share any features: one might be an experience I’d have with my eyes closed (shaggy coat feeling, barking noises), and another might involve visual impressions of a dog. Both could verify ‘x is a dog.’

32. Only So Much Time… Obviously, I can’t re-cover every objection we considered to the idea theory and then see how the verificationist does with respect to that question. BUT, that doesn’t mean that wouldn’t be an interesting paper topic for you to do.

33. Theoretical Concepts One last issue though. Verificationism was thought to have particular trouble with theoretical concepts (that is, with representing theoretical entities) like electrons or DNA. (These are called “theoretical entities” because we can’t observe them directly, but their existence is confirmed by their characteristic effects as described by our scientific theories. Example: effects of charged particles in cloud chambers.)

34. Idea Theory vs. Theoretical Entities The idea theory had it pretty bad with respect to such entities, but no one who lived at the time the idea theory was big knew this. For all anybody knew, particles were very much like mental pictures of little tiny pool balls. But now its implausible to think that anyone’s “mental images” of an electron come close to resembling electrons.

35. Verificationism vs. Theoretical Entities Verificationism was fine here, at least insofar as you could say that the behavior of the gas in the cloud chamber verified the existence of electrons, even though it didn’t resemble them.

36. The Problem The problem was that the meanings of scientific terms was supposed to be fixed in advance. Yet for many theoretical terms, it took years or decades after their introduction for us to discover any way of verifying claims about them. (Compare: ‘x is a Higgs Boson.’) So did claims about electrons, positrons, mesons, or whatever not mean anything until we discovered ways of verifying them. And did we discover their meanings then?

37. Problems for verificationism

38. Too Little is Meaningless The logical empiricists wanted to say that sentences like “The Absolute is Perfect” and “God exists” are meaningless. If you’re of that persuasion, you’re likely to think that “Either some socks are cotton or the Absolute is Perfect” and “Either God exists or snow is purple” are also meaningless. But the latter two clearly have conditions that would verify them.

39. Too Much Is Meaningless A bigger focus of criticism, however, was that according too the verifiability criterion, too much is meaningless, including: • Statements about the past or future. • Negative existentials. • Positive universals. • Certain positivist doctrines.

40. Statements about the Past/ Future One objection to the verifiability criterion was that it made statements about the distant past or the distant future meaningless, since there is no way of verifying, for example, the statement “T. Rex had a blue tongue” or “Hats will be popular among the first humans that colonize Alpha Centauri.”

41. A Confusion This objection is a little bit confused. Positivists don’t claim that for any meaningful sentence, there actually exists evidence you could find that would (when you found it) confirm that sentence. This would imply that every meaningful sentence was true. To be meaningful, a sentence just has to have verification conditions– it has to be possible for there to be circumstances that verify it.

42. A Confusion So I could, possibly, verify that T. Rex had a blue tongue by finding a perfectly preserved frozen T. Rex with a blue tongue. Sure, that won’t happen, but that’s not the point. Compare “God exists”– here, no experience will verify that claim, not even possible experience.

43. Reformulation However, this response only goes so far. What sort of evidence now could conclusively show that hats will be popular on Alpha Centauri? Additionally, we can reformulate the objection. Events outside my light-cone cannot affect me. So in what sense is it even possible to verify “A dinosaur outside my light-cone has a blue tongue”?

44. Verifiability “In Principle” However, the objection isn’t so simple: complex sentences like this were supposed to be built out of protocol sentences like ‘x is a T. Rex’ and ‘x is blue’ and ‘x is a tongue.’ Each of these has verification conditions. So we can say that a sentence is verifiable in principle if it is a logical construct out of protocol sentences, each of which is verifiable in the old sense.

45. Verifiability “In Principle” Russell pointed out however that some statements that seem meaningful are not verifiable in principle: • Neptune existed before it was discovered. • Atomic war will kill everyone. Someone couldn’t verify (1) before the discovery of Neptune, and they couldn’t verify it afterward either! Similar remarks go for (2).

46. The Verifiability Criterion Itself Consider the verifiability criterion: “a sentence is meaningless unless some finite procedure can conclusively verify its truth.” If this criterion is meaningful, then it must be that some finite procedure can conclusively verify the claim that a sentence is meaningless unless some finite procedure can conclusively verify its truth. But what procedure would that be? (Also note that the criterion doesn’t meet the special exception, because it’s not a logical truth either.)

47. Kicking Away the Ladder “My propositions serve as elucidations in the following way: anyone who understands me eventually recognizes them as nonsensical, when he has used them - as steps - to climb beyond them. He must, so to speak, throw away the ladder after he has climbed up it.” (Wittgenstein, TractatusLogico-Philosophicus, 6.54)

48. Existentials and Universals Here’s a(n incomplete) typology of claims: Positive existential: There is an F that is G. Negative existential: There is no F that is G. Positive universal: Every F is G. Negative universal: Not every F is G.

49. Existentials and Universals Positive existential claims and negative universal claims can be verified by a finite number of experiences. For instance, it suffices to observe just one cow that is dangerous to know that: • There is a cow that is dangerous. • Not every cow is safe.

50. Existentials and Universals However, negative existentials and positive universals cannot be verified by a finite number of claims. If I observe one billion cows that are dangerous, I still have not shown conclusively: • There is no cow that is safe. • All cows are dangerous.